Well cross-over apparatus for selective communication of flow passages in a well installation

ABSTRACT

A well flow system, including one or more flow conductors disposed in a well having a casing annulus, means interconnecting the conductor or conductors and/or annulus, and a fluid-actuated valve in at least one of the flow conductors for selectively communicating the conductor or conductors and/or the annulus of the well responsive to a pressure differential applied across the valve and controlled from the surface. The flow system is adapted to well producing and well treating procedures. A number of different flow conductor, well annulus, and valve arrangements are shown with provision in each system disclosed for hydraulic control of a down-hole valve to communicate selected combinations of flow passages of the conductors and the well annulus.

al llmte States atent [151 3,666,01 2

Sizer et al. 51 May 30, 1972 [54] WELL CROSS-OVER APPARATUS FOR3,533,430 10/1970 Fredd 166/224 SELECTIVE COMMUNICATION OF 3,554,2811/1971 Ecuer ...166/224 W ASS AGES IN A WELL 3,441,084 4/1969 Fredd..l66/189 INSTALLATION Primary Examiner-James A. Leppink [72] Inventors:Philllp S. Sizer; Albert W. Carroll, both of A wrney-H- M h w G rl ndDallas, Tex. [73] Assignee: Otis Engineering Corporation, Dallas, Tex.[57] ABSTRACT A well flow system, including one or more flow conductors[22] 'Flled' 1970 disposed in a well having a casing annulus, meansintercon- [21] Appl. No.: 91,751 necting the conductor or conductorsand/or annulus, and a fluid-actuated valve in at least one of the flowconductors for selectively communicating the conductor or conductors;J.tS.CCl| and/or the annulus f the responsive t a e u dif. E d h 3 189224 ferential applied across the valve and controlled from the sure oare face. The flow system is adapted to well producing and well Referenes Cited treating procedures. A number of different flow conductor,

c well annulus, and valve arrangements are shown with provi- UNITEDSTATES PATENTS sion in each system disclosed for hydraulic control of adownhole valve to communicate selected combinations of flow g d gppassages of the conductors and the well annulus.

re 3,494,420 2/1970 Sizer 166/3 13 23 Claims, 32 Drawing FiguresPatented May 30, 1972 3,666,012

11 Sheets-Sheet 1 Fig.2?)

INVENTORS Phillip S. Sizer BY Albert W.Corroil ATTORNEY Patented May 30,1972 13,66,012

11 Sheets-Sheet 2 Phillip S. Sizer BY Albert W. Carroll RMQDM ATTORNEYPatented May 30, 1972 3,666,U12

11 Sheets-Sheet 5 f //n F 7760 54 203 3/ in Q 7 /6/ M4 Fig.8 Fig.9

INVENTORS' Phillip S. Sizer BY Albert W. Carroll w My QM.

ATTORNEY Patented May 30, 1972 3,666,012

11 Sheets-Sheet 4 ATTORNEY Patented May 30, 1972 11 Sheets-Sheot s Q JAINVENTORS Phnllip S. Sizer BY Albert W.Corro|l ATTORNEY Patented May 30,1972 11 Sheets-$heet 6 INVENTORS Phillip S. Sizer y Albert CGI'FOHATTORNEY Patented May 30, 1972 3,66,012

1 1 Sheets-Sheet 7 BY Albert W. Carroll ATTORNEY Patented May 30, 1972ll Sheets-Sheet 11 mu mwmhm /wmmmvwm A 15,.

WELL CROSS-OVER APPARATUS FOR SELECTIVE COMMUNICATION F FLOW PASSAGES INA WELL INSTALLATION This invention relates to well tools, and moreparticularly relates to well flow systems for remote hydraulic controlof flow in passages in a well bore.

More and more, sought-after earth fluids, such as oil and gas, becomeincreasingly difficult to find and produce and, when found, are often inremote, physically inaccessible locations. One preferred approach to asolution to the more trying circumstances of such problems resides in awell flow system which is remotely controllable and which may includemeans for fluid transport of some of the control mechanism employed,such as the fluid operated valves to and from the down-hole equipmentfrom the surface. Accordingly, it is a particularly important object ofthe invention to provide a new and improved well flow system for flowcontrol between selected flow paths in a well.

It is another object of the invention to provide a well flow controlsystem which is manipulated from the surface by fluid pressure means.

It is another object of the invention to provide a well system in whichcontrol valves may be pumped to and from operating locations in a well.

It is a further object of the invention to provide a well flow controlsystem including valve means which are opened and closed responsive tofluid pressure differentials applied within a well bore between selectedflow passages in the bore.

It is another object of the invention to provide a well flow controlsystem in which fluid communication is controllable through at least oneflow conductor in the well above a packer and a portion of the flowconductor communicating with a producing formation around the well belowthe packer.

It is another object of the invention to provide a well flow systemwhich includes at least one flow conductor for producing well fluidsfrom a well bore and at least one other flow passage selectivelycommunicated with the flow conductor for applying a pressuredifferential to valve means in the flow conductor for controlling thefunction of such valve means.

It is still another object of the invention to provide a well flowsystem including a plurality of flow passages defined by a flowconductor communicating through a valve to a packedoff producingformation, a flow conductor extending to such valve for use incontrolling such valve, and a flow conductor connected with an annulusportion in the bore of the well isolated from the producing formation.

It is still another object of the invention to provide a well flowsystem including a flow conductor communicating through a valve to apacked-off producing formation, such flow conductor also communicatingthrough the valve to an annulus in the well bore isolated from theproducing formation, and a flow conductor connected with the annulus forpressure control of the valve by adjustment of a pressure differentialbetween the first flow conductor and the annulus.

It is still another object of the invention to provide a well flowsystem including at least two flow conductors in a well borecommunicating with each other through a fluid pressure controllablevalve and communicating through such valve with the annulus of the welland including a flow conductor communicating with the annulus whereby apressure differential may be applied at the valve between either of theflow conductors communicating and between the annulus and the flowconductor.

It is still another object of the invention to provide a well flowsystem including at least two flow conductors one of which includes apressure controllable valve through which such conductor communicateswith the other flow conductor, both of such conductors communicatingwith the well bore below such valve and another flow conductorcommunicating with the annulus of the well bore around the first twomentioned flow conductors.

It is still another object of the invention to provide a well flowsystem including at least two flow conductors one of which has a fluidoperated valve with a bypass around such valve, the valve isolating theflow conductors from each other at one position and at another positioncommunicating the flow conductors while shutting off a portion of oneconductor below the valve.

It is still another object of the invention to provide a well flowsystem including at least two flow conductors interconnected through afluid-actuated valve, the flow conductor in which the valve ispositioned having a bypass around the valve, the portion of such flowconductor communicating from above the valve through the valve with theother flow conductor, while the portion of such flow conductor below thevalve is isolated from the other flow conductor, the valve beingoperable responsive to a differential pressure between the flowconductors.

It is another object of the invention to provide a well system havingfirst and second flow conductors, a cross-over between the conductors,and a valve in the first flow conductor isolating the conductors at oneposition and communicating the conductors at another position whileshutting off the first conductor below the valve, the casing beingisolated at all times, the valve functioning responsive to acasing-first conductor pressure differential.

It is another object of the invention to provide a well flow systemhaving interconnected first and second flow conductors communicatingthrough a valve in the first flow conductor and having a bypass alongsuch first flow conductor around the valve, the valve being operableresponsive to a pressure differential between the casing annuluspressure and pressure in the first flow conductor, the flow conductorsbeing isolated from each other and from the casing at one valveposition, and the second of the flow conductors being communicated withthe casing annulus and the lower portion of the first conductor isolatedat a second valve position.

It is still another object of the invention to provide a well flowsystem including at least a pair of interconnected flow conductors witha fluid-actuated valve in the first of such flow conductors and a bypassin such conductor around the valve, the valve isolating the flowconductors from each other at one valve position while the portion ofthe first flow conductor above the valve is conununicated through thevalve with the casing annulus and the portion of the first conductorbelow the valve is isolated at a second valve position.

It is still another object of the invention to provide a well flowsystem including at least a pair of interconnected flow conductors, afirst of such flow conductors including a fluidactuated valve and havinga bypass around such valve, the flow conductors being isolated from eachother at a first valve position, the casing annulus being isolated atall times, and the valve being moved to a second position responsive tocasing pressure to communicate the flow conductors and isolate theportion of the first flow conductor below the valve.

It is still another object of the invention to provide a well flowsystem having at least a pair of flow conductors interconnected, thefirst of such conductors having a casing pressure responsivefluid-operated valve and a bypass around the valve, the casing annulus,the first flow conductor above the valve, and the second flow conductorbeing simultaneously communicated through the valve while the first flowconductor below the valve is isolated from the casing annulus and thesecond flow conductor.

It is still another object of the invention to provide a well flowsystem having at least a pair of flow conductors interconnected througha fluid operated valve disposed in a first of the flow conductors andincluding a sliding sleeve valve disposed in the second of the flowconductors for isolating the two flow conductors at the valve from eachother, the first of the flow conductors having bypass flow passagesaround the valve, the flow conductors above the valve being communicatedwith each other when the valve is at a lower position with the lowerportion of the first flow conductor below the valve being isolated, andthe flow conductors being fully isolated from each other when the valveis in an up position.

It is still another object of the invention to provide a well flowsystem having at least two flow conductors interconnected through afluid-operated valve disposed in one of the flow conductors, each of theflow conductors having landing and locking recess means for placing avalve in either of the flow conductors at a cross-over connectionbetween them, each of the flow conductols having a bypass around thelanding means for bypassing the valve when placed in either of the flowconductors, the valve being adapted to permit communication between thetwo flow conductors while isolating the portion of the flow conductorcontaining the valve below the valve from the upper portion of such flowconductor and from the other flow conductor, the valve being operableresponsive to a pressure differential between the flow conductors, andthe flow conductors being isolated from the casing annulus.

It is another object of the invention to provide a well system havingfirst and second flow passages, a valve in the first passage forisolating the passages at a first valve position while allowing flowalong the first passage and for communicating the passages at a secondvalve position responsive to a pressure exterior of the first passagewhile isolating the first passage below the valve.

It is another object of the invention to provide a well valvearrangement for use in a well flow control system which includes aside-pocket type landing nipple in one flow conductor connected througha cross-over flow passage with another flow conductor whereby a valve inthe side pocket controls communication between the flow conductors.

It is another object of the invention to provide a valve arrangement fora well system including a pair of laterally spaced side-pocket typelanding nipples included in first and second flow conductors andconnected by a cross-over passage whereby a flow control valve may bedisposed in the side pocket of either of the landing nipples forcontrolling fluid communication between the flow conductors.

It is another object of the invention to provide a well arrangementincluding side-pocket landing nipples in spaced tubing strings arrangedin an over-under nested relationship and interconnected by a flow tubefor communicating the tubing strings with each other through the sidepockets whereby a valve disposed in either of the side pocketsselectively controls communication between the tubing strings throughthe side pockets.

It is another object of the invention to provide a body member for usewith laterally spaced tubing strings and including a side-pocket typelanding nipple along one side ofthe body and a longitudinal flow passagealong the other side communicated with the landing nipple at the sidepocket by a lateral flow passage for selectively communicating thetubing strings connected with the body by means of a fiow control valvedisposed in the side pocket.

It is another object of the invention to provide a body member having apair of laterally spaced side-pocket type landing nipples formed thereinand a cross-over flow passage communicating the nipples at the sidepockets whereby fluid flow is controllable between the spaced landingnipples by a valve placed in either of the side pockets for selectivelycommunicating parallel tubing strings connected with the body.

These and further objects of the invention will be apparent from readingthe following description of preferred embodiments of the inventiontaken in conjunction with the accompanying drawings wherein:

FIG. 1 is a fragmentary schematic view in longitudinal section of a wellhaving a flow system in accordance with the invention;

FIG. 2 is a view similar to FIG. 1 of another form of well flow systemembodying the invention;

FIG. 3 is a view similar to FIG. 1 of a still further form of well flowsystem embodying the invention;

FIG. 4 is a view similar to FIG. 1 of another form of well flow systemembodying the invention;

FIG. 5 is a fragmentary view in longitudinal section of one form ofvalve which may be used in the well systems of FIGS.

1-4 for flow control between the flow passages defined in the wellsystems;

FIG. 6 is a schematic view in longitudinal section of another well valvewhich may be employed in the well systems of FIGS. 1-4 showing the valveat an upper end position;

FIG. 7 is a view similar to FIG. 6 showing the well valve at a lower endposition;

FIG. 8 is a longitudinal fragmentary view in section of flow conductorsand a well valve in a system similar to that shown in FIG. 4 with thevalve at an upper end position;

FIG. 9 is a view similar to FIG. 8 with the valve moved to a lower endposition;

FIG. 10 is a fragmentary longitudinal sectional view of flow conductorsand a well valve for a system similar to that of FIG. 4 showing the wellvalve at an upper end position;

FIG. 11 is a view similar to FIG. 10 with the valve moved to a lower endposition;

FIG. 12 is a longitudinal fragmentary sectional view of another flowconductor and well valve arrangement for a system similar to FIG. 3showing the valve at an upper end position;

FIG. 13 is a view similar to FIG. 12 illustrating the valve at a lowerend position;

FIG. 14 is a fragmentary longitudinal sectional view of another flowconductor and well valve arrangement for a system similar to FIG. 3 withthe valve at an upper end position;

FIG. 15 is a view similar to FIG. 14 with the valve moved to a lower endposition;

FIG. 16 is a longitudinal sectional view of another flow conductor andwell valve arrangement for a well system similar to FIG. 3 with thevalve at an upper end position;

FIG. 17 is a view similar to FIG. 16 with the valve moved to a lower endposition;

FIG. 18 is a longitudinal fragmentary sectional of another arrangementof flow conductors and well valve for a well system similar to FIG. 3showing the valve at an upper end position;

FIG. 19 is a view similar to FIG. 18 with the valve moved to a lower endposition;

FIG. 20 is a longitudinal fragmentary sectional view of anotherarrangement of flow conductors and a well valve for a well flow systemsimilar to FIG. 3 showing the valve at an upper end position;

FIG. 21 is a view similar to FIG. 20 showing the valve moved to a lowerend position;

FIG. 22 is a longitudinal fragmentary sectional view ofa still furtherform of flow conductor and well valve arrangement for a system similarto that of FIG. 3 utilizing a sliding sleeve valve in one flow conductorand a fluid responsive control valve in the other flow conductor,showing the valve at an upper end position;

FIG. 23 is a fragmentary longitudinal view in section of a portion ofthe wall system of FIG. 22 with the well valve removed and the slidingsleeve valve moved upwardly to a closed position;

FIG. 24 is a fragmentary longitudinal view in section of another form offlow conductor and well valve arrangement including a bypass along eachflow conductor and means for locking the well valve in either of theflow conductors; and

FIG. 25 is a broken, longitudinal, fragmentary view in section of a sidepocket form of landing nipple for a well control valve.

FIG. 26 is a broken longitudinal fragmentary view in section of aside-pocket landing nipple in one tubing string connected by across-over to another tubing string;

FIG. 27 is a broken longitudinal fragmentary view in section ofinterconnected side-pocket type landing nipples included in adjacenttubing strings of a well;

FIG. 28 is a broken fragmentary longitudinal view in section of anover-under arrangement of interconnected side-pocket type landingnipples in adjacent tubing strings;

FIG. 29 is a broken fragmentary longitudinal view in section of aunitary body member having a side-pocket type landing nipple formedalong one side and an interconnected longitudinal bore defining a flowpassage along the other side for use with parallel tubing strings;

FIG. 30 is a view in section along the line 30-30 of FIG. 29;

FIG. 31 is a broken fragmentary longitudinal view in section along theline 31-31 of FIG. 32 of another unitary body structure for use withparallel tubing strings in a well and including a side-by-sidearrangement of interconnected sidepocket type landing nipples; and

FIG. 32 is a cross-sectional view along the line 3232 of FIG. 31 showingthe actual side-by-side positions of the two landing nipples of FIG. 31.

In accordance with the invention, a number of forms of a well systemembodying the invention are provided for well production and servicing.In its broadest concept the well system has a flow conductor defining afirst flow passage for well fluids flow and for well service fluids flowat separate selected times. One or more other flow passages are providedin the well system. At least two of the flow passages communicatethrough a valve operable in the first flow passage. At a first valveposition such two passages are isolated from each other while flow ispermitted to the surface through at least the first passage from belowthe valve. At a second valve position two of the flow passagescommunicate with each other. The pressure in the first flow passage isnormally above the other flow passage pressures to which the valve isexposed. The valve is moved from a first to a second position responsiveto an increase in pressure from exterior of the first flow passage. Atthe second valve position various well servicing procedures are carriedout.

Referring to FIG. 1, a well system 40 includes a well 41 having a wellcasing 42 provided with a surface well head 43. A flow conductor 44 issupported in the well for producing well fluids and for introducingfluids into the well during treatment procedures. The flow conductorincludes a surface control valve 45. A down-hole valve 50 is included inthe flow conductor for controlling flow through the conductor to thesurface and for providing one leg of a closed circuit flow path abovethe valve for tool pumping and well servicing purposes. A fluid controlline 51 having a surface valve 52 is connected through the well headinto the valve 50 for fluid pressure control of the valve 50 and toprovide a return flow path to the surface for certain well servicing andtool pumping functions. A suitable well packer 53 seals around the flowconductor within the casing below the valve 50 defining with the flowconductor and casing an upper well annulus 54 and a lower well fluidsproducing portion 55. A line 60 having a valve 61 is connected throughthe well head into the annulus 54 for fluid flow to and from the annulusfor various well control and servicing purposes.

The valve 50 as shown in greater detail in FIG. 5 includes a housing 62which may be formed integral with a section of the flow conductor 44 ormay be provided with connection means, such as threads at opposite ends,not shown, so that the valve may be installed in any suitable locationalong the length of the flow conductor 44 by threadedly engaging thehousing between adjacent sections of the conductor. The valve has aninternal concentrically disposed cylindrical body 63 provided with alongitudinal bore 64. The body 63 is inwardly spaced in the valvehousing 50 defining an annulus 65 extending substantially the length ofthe valve between the body and housing. The annulus 65 is closed at thelower end and open to the conductor 44 at the upper end. The body 63 isconnected by short conduit portion 70 to the housing 62 defining a flowpassage or side port 71 from exterior of the valve housing into thecentral bore 64. In the well system 40, the control in 51 is connectedinto the side port 71. The bore 64 is enlarged along a lower portion 72along which the body 63 is provided with side ports 73 communicating thecentral bore of the valve with the annulus 65 so that fluid may flowfrom the flow conductor below the valve through the valve into the flowconductor above the valve. Upper and lower valve seats 74 and 75,respectively, are formed in the valve body 63 at the opposite ends ofthe central bore portion 72 to receive a ball valve 80 which is movablebetween the upper and lower positions illustrated in FIG. 5. A removableplug 81 is locked in the upper end portion of the bore 64 by lockingdogs 82 which engage an internal annular locking recess in the body 63around the bore 64. A ring seal 84 supported on the plug 81 seals aroundthe plug with the wall of the bore 64. It will be apparent that the body63 could be fabricated with a solid closure at the upper end of the bore64 to perform the same function as the plug 81 so that fluids in thebore 64 are directed to the side port 71 of the valve. At the lowerposition of the ball valve 80 shown in solid lines in FIG. 5 no flow mayoccur through the valve downwardly into the flow conductor portion 444below the valve. At the upper position illustrated by the broken linerepresentation of the ball valve in FIG. 5, flow may not occur throughthe valve in the central bore 64 to the side port 71 in the valve.

The well system 40 allows well production upwardly through the flowconductor 44 and valve 50 from the well bore portion below the packer53. Also, the system permits closing the flow conductor at the valve sothere is no fluid communication to the lower producing portion of thewell bore while a closed circuit fluid flow pattern is established inthe well including the flow conductor 44 above the valve 50 and the line51. When the pressure in the producing portion 55 of the well bore belowthe packer, as communicated in the open lower end 440 of the flowconductor below the valve 50, is greater than the pressure in the line51 and the flow conductor 44 above the valve 50, the ball valve 80 isforced to an upper end position against the seat 75, closing off thebore 64 through the valve 50 so that well fluids being produced flowupwardly into the lower end 44a of the flow conductor into the valve 50and radially outwardly through the ports 73 below the ball valve. Thefluids then flow upwardly in the annulus 65 into the flow conductor 44above the valve to the surface. When it is desired to shut offproduction flow through the valve 50, the valve 45 may be closed, andwith the valve 52 open, the pressure may be increased through thecontrol line 51 until the ball valve 80 is forced downwardly from theupper end positionto a lower end position on the seat 74, therebyshutting off communication through the valve 50 into the flow conductorportion 44a below the packer 53. With the valve 80 at the lower endposition, communication is established through the valve 50 between thecontrol line 51 and the flow conductor 44 above the valve 50. Fluidpressure is transmitted and flow may occur from the annulus 65 in thevalve 50 through the ports 73 above the valve 80 into the bore 64 andlaterally through the side port 71 into the control line 51. So long asthe pressure in the control line and upper portion of the flow conductor44 exceeds the pressure in the production portion 55 of the well borebelow the packer, the ball valve will remain at the lower seatedposition, and fluids may be pumped back and forth as desired through thewell system along a flow path defined by the control line 51, the valve50, and the flow conductor 44 above the valve 50. When well productionis again desired through the flow conductor to the surface, the pressureapplied to the control line is decreased until the formation pressurebelow. the packer exceeds the pressure above the ball valve 80 so thatthe ball valve is moved to the upper end position shutting ofi'communication into the control line 51 and permitting upward productionflow to again occur to the surface through the valve 50 and theconductor 44.

During production and treating procedures in the well the pressure inthe annulus 54 may be controlled through the line 60 and valve 61. Theannulus 54 above the packer 53 may be maintained liquid filled ifdesired. In the particular arrangement illustrated in FIG. 1, nocommunication is provided from the annulus 54 into either the controlline 51 or the conductor 44. Thus, in the system of FIG. 1, utilizingthe valve of FIG. 5, the annulus is isolated from the productionconductor and control line, production may be had through the main flowconductor 44, and the producing zone below the packer 53 in the wellbore may be shut off by pressure in the flow conductor and control lineabove the valve 50, while circulation as desired is accomplished betweenthe control line and flow conductor above the valve.

FIG. 2 illustrates a well system 90 embodying the invention whichincludes the casing 42, the well head 43, and the flow conductor 44. Theflow conductor has the surface valve 45 for control of flow into and outof the flow conductor. The packer 53 seals within the casing around theflow conductor below the valve 50. The side port 71 in the valve 50communicates directly with the annulus 54 of the well bore above thepacker 53, while communication at the well head into the annulus isprovided through the line 60 and valve 61. The well in the system ofFIG. 2 is produced through the flow conductor and the valve 50 in thesame manner as the system 40 with well fluids flowing from below thepacker 53 upwardly through the flow conductor 44 so long as the fluidsare at a pressure in excess of both the pressure in the flow conductor44 above the valve 50 and the pressure in the annulus 54. The ball valve80 may be forced downwardly to shut ofl production into the flowconductor by raising the annulus pressure through the line 60 to a valuesufficient to force the ball valve 80 to the lower seated position. Solong as the valve 80 is held on the seat 74, the well system may becirculated through the flow conductor 44 above the valve 50, through thevalve 50, and through the annulus 54. Fluids may flow in eitherdirection through the annulus and flow conductor 44 above the valve 50so long as the pressure is maintained above the formation fluidspressure to keep the valve 80 seated at the lower end position.

Another form of well system 100 embodying the invention is shown in FIG.4. Functionally the system 100 is essentially the same as the system 40in FIG. 1 with the exception of the packer 53 which is not included inthe system 100. Like components have been given the same referencenumerals in the system 100 as used in the system 40 in FIG. 1. A flowconductor 101 having a valve 102 is connected through the well head intothe side port 71 of the valve 50. The conductor 100 performs the samefunction as the control line 51 but is, however, capable of more flowand thus it would be more adaptable to pumping well tools to and fromthe valve 50. In the well system 100, so long as the pressure in thewell bore exceeds the pressure in the conductor 101, the ball valve 80is held at the upper end position allowing well fluids to flow to thesurface through the valve 50 and the conductor 44. Since no packer ispresent in the well, the pressure in the well bore within the casing mayresult from well formation pressure or could be supplied in the line 60connected into the well head. In this well system, maintenance of apressure in the well bore either from formation fluids or as appliedexternally through the line 60, permits circulation between the wellbore and the flow conductor 44 to the surface irrespective of the sourceof the well bore pressure. When the pressure in the conductor 101 israised to a level exceeding the well bore pressure, the valve 80 isforced downwardly on the seat 74 permitting circulation through the wellbetween the flow conductors 44 and 101.

Another form of well system 110 embodying the invention, is shown inFIG. 4 wherein like components are referred to by the reference numeralsused with respect to FIGS. 1, 2, and 3. The flow conductor 44 isconnected through a cross-over connection 111 at the valve 50 to aparallel flow conductor 112 which includes a surface valve 113 above thewell head. As in the other well systems shown, the annulus 54in the wellcasing around the flow conductors communicates at the well head with aline 60 having a valve 61 to permit the control of pressure conditionsin the annulus. The flow conductors 44 and 112 may extend to suitablypacked-off producing zones of the well bore, not shown, which may bedefined above an upper dual packer of conventional design sealing withinthe well casing around both of the flow conductors, with one of the flowconductors being perforated below the dual well packer for production ofthe well zone immediately below the packer. The other of the two flowconductors may extend through a lower single well packer to a secondlower production zone so that the two flow conductors are utilized forthe production of separate zones in the well bore, while the mechanismof the cross-over connection and the valve 50 will permit establishmentof a circulation pattern between the flow conductors while shutting offthe lower portion 44a of the flow conductor 44 below the valve 50.Depending upon well conditions, a suitable standing valve, not shown,may be included in the flow conductor 112 so that when the pressures areadjusted to circulate through the well in the flow conductors throughthe valve 50, the standing valve will prevent application of thecirculation pressure to the well formation communicating with theconductor 112. In operating the well system 110 for dual production fromseparate producing zones, the higher pressure of the two producing zonesis communicated with the flow conductor 44 to achieve simultaneous dualproduction. The ball valve in the valve 50 must be at its upper positionas shown in FIG. 5 for isolating the two flow conductors through thecross-over connection 111 while permitting flow from below the valve 50through the flow conductor 44 at the same time flow is occurring fromthe other lower pressure producing zone in the conductor 112. It will beevident that if the higher pressure were in the flow conductor 112, thecommunication of this pressure through the cross-over flow passage 71 inthe valve 50 would force the ball valve 80 to a lower seated positionthereby shutting off the flow conductor portion 44a below the valve 50to preclude production from the zone communicating with the conductorportion 44a. For circulation between the flow conductors through thevalve 50, the pressure may be raised above the ball valve 80 by pumpinginto the flow conductor 112 until the pressure applied through thepassage 71 exceeds the pressure in the flow conductor 44 to force theball valve downwardly to the lower end position so that pumpingcirculation may occur between the portion of the flow conductor 44 abovethe valve 50 and the flow conductor 112. The increase in pressure in theflow conductor 112 closes the standing valve, now shown, in the flowconductor 112 below the cross-over connection so that the producingformation communicating with the conductor 112 is not subjected to thecirculation pressure. Once the ball valve 80 is forced to the lower endposition, pumping in either direction through the U-shaped flow pathdefined by the conductors 44 and 112 through the valve 50 may beachieved so long as the pressure is kept to a value sufficient to holdthe ball valve 80 on the seat 74. Obviously, the portion 44a of the flowconductor 44 below the valve 50 is not subjected to the circulationpressure.

It will be evident from the description of the well systems of FIGS. 1and 4, including the valve of FIG. 5, that in each instance, the wellvalve of the system is located in the first of a plurality of flowpassages in the well bore, is operable responsive to a pressure increasein one of the flow passages exterior of such first flow passage, andwhen so operated, functions to isolate the portion of the first flowpassage in the well bore below the valve. The first flow passage abovethe valve and such other flow passage communicate through the valve. Itwill additionally be recognized that in the instance of each of the wellsystems the well valve is in the flow passage which under normal welloperating conditions, is subjected to the higher of the pressures towhich the valve 50 is exposed. Thus, with respect to the systems ofFIGS. 1 and 2, when producing the well, the valve 50 is functioning toshut ofi the control line 51 in the system 40 and to isolate the wellannulus 54 in the system 90. Similarly, in the systems and of FIGS. 3and 4, the position of the valve in the higher pressure conductor servesto isolate the pair of parallel conductors of each system from eachother during production of the well.

FIGS. 6 and 7 illustrate a valve and cross-over assembly which isparticularly useful in the well systems of FIGS. 1 4. The assembly 120includes a housing 121 connectible by any suitable means into the flowconductor 44. An internal tubular body portion 122 is provided withinthe housing 121 concentrically spaced therein defining a central flowpassage 123 through the body and an outer annular flow passage 124around the body in the housing. The body 122 is connected by shortconduit section 125 providing a side port 130 communicating the exteriorof the valve housing with the central flow passage 123. The central flowpassage 123 has an upper principal portion 123a above an internalannular supporting shoulder 131 and a lower reduced portion 123bextending downwardly from the shoulder 131 to an internal annular valveseat 132. The lower portion 123b of the central flow passagecommunicates throughports of 133 in the internal housing portion 122with the annular flow passage 124. The internal housing 122 has aninternal annular locking recess 134 around and near the upper end of theupper central flow passage portion 1230. A removable valve 135 isreleasably locked in the central flow passage 123 of the valve assembly120 for controlling flow to the side port 130. The valve 135 has acylindrical body 140 provided along its upper end portion withexpandable and contractible locking dogs 141 adapted to engage thelocking recess 134 for locking the valve in the internal body portion122. The locking dog arrangement including the locking dogs 141 maycomprise any suitable conventional locking mandrel such as thosemanipulated by wireline techniques as illustrated on pages 3,832 of theComposite Catalog of Oilfield Equipment and Services, 1970-71 Edition,published by World Oil, Houston, Tex. The valve body 140 has an externalannular recess 142 in which ring seal 143 is disposed for sealing aroundthe valve body within the central flow passage 123. The valve body has avalve member and spring chamber 144 for a vertically movable valve 145which includes an upper spring retainer flange 150, a valve rod 151, anda valve member 152 provided with an external ring seal 153 for sealingaround the valve member within the lower flow passage portion 123b. Thevalve 145 is biased upwardly by a spring 154 confined between the upperspring flange 150 and an internal stop flange 152 formed in the valvebody 140 at the lower end of the chamber 144. The valve member ismovable between an upper end position as in FIG. 6 and a lower endposition as in FIG. 7. At the position of the valve in FIG. 6, the valvemember 152 is disposed between the side port 130 and the ports 133communicating with the central passage portion l23b so that the port 130and the ports 133 are isolated from each other. Thus, at this valveposition in the well system flow may occur from the lower flow conductorportion 44a upwardly and outwardly through the ports 133 into theannular space 124 from which the fluids flow up wardly into theconductor 44. The flow through the well conductor 44 is isolated fromthe flow passage connected with the side port 130, which may be the wellannulus or another flow conductor. The upward force on the valve member145 is the combination of the force of the spring 154 biasing the valveupwardly and the pressure in the well fluids in the flow passage portion123b below the valve member 152. An increase in the pressure appliedthrough the side port 130 to the valve member 152 above the ring seal153 to a level at which the force of the pressure exceeds the upwardforce on the valve member moves the valve to a lower end positionagainst the seat 132. At this lower end position, the lower conductorportion 440 is isolated from the well conductor above the seat 132,while the ports 133 and the side port 130 communicate through thecentral flow passage portion 12312 so that the well may be circulatedbetween the upper portion of the flow conductor 44 above the valve andthe side port 130. So long as the pressure above the valve member issufficient to hold it at the lower end position of FIG. 7, the well maybe circulated with the flow conductor portion 440 below the valveisolated. When the pressure above the valve member is reduced to a levelat which the force of the spring and the pressure below the valve membermay lift the valve member, the valve member is returned to the upper endposition to again effectively close the side port 130 and permit wellflow through the flow conductor 44a from below the valve. Thus, wellsystems including the valve are responsive to casing, control line, orparallel tubing, depending upon the particular well system, for shuttingoff the lower portion of the flow conductor containing the valve andestablishing well circulation through the valve. The valve cannot beopened or moved to a circulating position by increasing the pressure inthe flow conductor containing the valve.

FTGS. 8 and 9 show another valve and cross-over assembly which may beused in well systems similar to those of FIGS. 3 and 4. The systemincludes a flow conductor 161 having a lower portion 161a which mayextend to a producing formation along the well bore. The valve assemblyincludes a removable spring-biased valve 162 which has a valve member163 supported on a valve rod 164 biased in an upward direction by aspring 165. The lower flow conductor portion has an annular valve seat170 engagable by the valve member 163 at a lower end position forisolating the conductor portion 161a below the valve assembly. A by-passflow line 171 is connected at opposite ends into the flow conductor 160around the valve 162. The lower end of the by-pass line connects intothe flow conductor 160 above the valve member 163 when the valve memberis at a lower end seated position as illustrated in FIG. 9. Theconductor 161 communicates through a crossover connection 172 intoanother flow conductor 173 which extends upwardly to the well head anddownwardly to a producing formation, not shown, communicating with thewell bore. The flow conductors 161 and 173 extend through a suitable,conventional dual packer 174 which seals within the well casing 42around both of the flow conductors. The flow conductor 173 and the lowerportion 161a of the conductor 161 may extend to separate producing zonesin the well bore to permit dual production in the well system. The flowconductor 173 is preferably provided with a standing valve, not shown,at a depth below that portion of the conductor shown in FIG. 8 to permitproduction upwardly through the flow conductor while precluding downwardflow through the conductor when the well is being circulated through thevalve assembly 160.

In the operation of the valve system 160, with the valve position asillustrated in FIG. 8 the well may be produced through both of the flowconductors simultaneously. Well fluids entering the flow conductor 173flow through the conductor directly to the surface. Well fluids enteringthe lower conductor portion 161a flow upwardly in the conductor to thejunction of the conductor with the by-pass line 171. The valve member163 diverts the well fluids into the by-pass line through which theyflow around the valve 162 and back into the flow conductor 161 above thevalve and to the surface. The valve member 163 at the position of FIG. 8prevents communication between the flow conductors 161 and 173. Thenormal production pressure in the conductor 161 exceeds the pressure inthe conductor 173. The force of the pressure in the flow conductor 161below the valve member 163 and the spring hold the valve at the upperend position at which it remains to isolate the two flow conductors solong as the combined force from the spring and pressure in the conductor161 exceeds the downward force on the valve member 163 from the pressurein the flow conductor 173. When well circulation from the surfacethrough the flow conductors 161 and 173 and the valve assembly 160 isdesired, the relative pressures in the flow conductors are adjusted asby increasing the pressure in the conductor 173 to a value at which thedownward force on the valve member 163 exceeds the upward force of thespring 165 and the pressure in the conductor portion 161a below thevalve member. The valve member 163 is forced downwardly to the lower endposition of FIG. 9 at which the valve member seats on the valve seat170.

At the lower end position of the valve member the lower conductorportion 161a is isolated, and the flow conductors 161 and 173communicate through the valve bore 166 above the valve member 163 andthe cross-over connection 172. Downward flow in the conductor 173 isprevented by virtue of the standing valve in the conductor, not shown.So long as sufficient pressure is maintained above the valve member 163to keep it at the lower end position, flow may occur from the well headin either direction through the flow passage system including the flowconductors 161 and 173. For example, if fluids are pumped into the wellthrough the conductor 161, they pass downwardly in the conductor,through the bypass line 171, into the valve bore 166 above the valvemember 163, and across through the cross-over connection 172 into theflow conductor 173 through which the fluids return to the surface. Thereverse of this flow pattern is followed by fluids pumped into the flowconductor 173 at the surface with returns moving upwardly in the flowconductor 161. There is no communication with the annulus 54 during suchwell circulation. After the well has been serviced as desired, reductionin the pressure in the flow conductor 173 permits the valve member 163to return upwardly to the upper end position at which the flowconductors are again isolated from each other, and simultaneous wellproduction may occur in the conductors. The annulus 54 may be maintainedliquid full in view of the fact that there is no communication betweenthe annulus and either of the flow conductors.

Another form of well system embodying the invention is illustrated inFIGS. and 11. A pair of flow conductors 180 and 181 are disposed in thecasing 42 through a dual packer 183 extending to producing formations,not shown. The flow conductor 180 may include a standing valve, notshown, to prevent back flow during well circulation between the flowconductors. The flow conductors are interconnected through a valveassembly 184 by a cross-over connection 185. The valve assembly includesa removable valve 190. The valve has a valve stem 191 which islongitudinally movable in a valve bore 192 which communicates at theupper end thereof with the flow conductor 181 and at the lower end witha lower portion 181a of the flow conductor 181. The valve stem is biasedupwardly by a spring 193. A pair of spaced upper and lower valve members194 and 195 are supported on the valve stem above and below thecross-over connection 185 between the flow conductors. The lower flowconductor portion 181a has an annular valve seat 200 engagable by thelower valve member 195 when the valve stem and members are at a lowerend position. A side port 201 in the conductor 181 communicates the wellannulus 54 around the flow conductors with the valve bore 192 above theupper valve member 194 whereby the valve functions responsive to theannulus pressure. A by-pass line 202 connects the flow conductor 181above the valve 190 with the lower flow conductor portion 181a below thevalve member 195. The by-pass line communicates through a port 203 atits upper end with the flow conductor above the valve and through a port204 at its lower end with the lower portion of the valve bore 192. Theport 204 is spaced above the valve seat 200 so that the valve member 195when on the seat 200 is below the port 204. Well fluids from a formationcommunicating with the flow conductor 180 flow directly to the wellhead. When the valve is at the position of FIG. 10, the well fluids froma formation communicating with the lower flow conductor portion 181aflow through the side port 204, the by-pass line 202 and into the upperflow conductor portion 181 through the side port 203, thereby passingthe valve 190. The port 201 communicates the casing annulus 54 aroundthe flow conductors with the valve bore 192 above the upper valve member194. So long as the force of the pressure within the flow conductor 181below the valve member 195, combined with the force of the spring 193,exceeds the force of the pressure applied from the casing annulusthrough the port 201 to the upper valve member 194, the valve remains atthe upper end position of FIG. 10, isolating the two flow conductors forsimultaneous production through both conductors. The pressure within theflow conductor 180 as applied to the valve members through thecross-over connection 185 does not affect the valve; thus, regardless ofthe pressure in such flow conductor, the valve position is not altered.The upper and lower valve members are of the same cross sectional area,and thus the upward force applied to member 194 is counterbalanced bythe downward force applied to member 195. The upper valve member 194,irrespective of the valve position, always remains between thecross-over connection 185 and the port 201 to the casing annulusprecluding communication at all times between the casing annulus andeither of the flow conductors. When communication is desired for fluidflow between the flow conductors and 181, the pressure relationshipbetween the flow conductor 181 below the lower valve member 195 and thecasing annulus pressure is changed, such as by increasing the casingannulus pressure until the force from such pressure as applied throughthe port 201 to the upper valve member 194 exceeds the force of thespring 193 and the force of the pressure in the flow conductor 181applied to the lower valve member 195. The valve is moved downwardly tothe lower end position shown in FIG. 11, at which position the lowerflow conductor portion 181a is isolated by the seating of the lowervalve member 195 on the valve seat 200 below the port 204 leading to theby-pass line 202. With the valve member 195 below the port 204 theconductors 180 and 181 communicate through the valve bore 192 whichconnects with the cross-over connection 185 and the port 204. Thus,fluid flow may occur between the flow conductor 180 and the upperportion of the flow conductor 181 through the port 203, the by-pass line202, the port 204, the valve bore 192 between the lower valve member andthe upper valve member 194, and the cross-over connection 185 into theflow conductor 180. The casing annulus remains isolated from the flowconductors. So long as the casing annulus pressure is maintainedsufficiently above the pressure in the flow conductor portion 181a belowthe lower valve member 195, fluid may flow in either direction betweenthe flow conductors 180 and 181. When return of the valve to the upperend position of FIG. 10 is desired, the casing pressure is reduced topermit the spring 193 and the pressure below the lower valve member 195in the lower conductor portion 181a to lift the valve back upwardly.Thus, the valve system shown in FIGS. 10 and 11 permits the isolation ofparallel flow conductors from each other and the communication of suchflow conductors with each other responsive to casing pressure whileisolating the lower portion of the flow conductor containing the valvefrom the remainder of the well system, at all times isolating the casingannulus pressure from both of the flow conductors.

FIGS. 12 and 13 illustrate a still further form of valve arrangement ina well system which permits dual production at one valve position andcommunicates the casing annulus and one flow conductor while isolatingthe other flow conductor at another valve position. Referring to FIGS.12 and 13, a pair of flow conductors 210 and 211 are supported in thecasing 42 through a dual well packer 212 extending in the well to dualproduction zones, not shown. The flow conductor 210 includes a standingvalve, not shown, to prevent back-flow during well servicing proceduresinto the producing formation communicating with the flow conductor. Theflow conductors communicate through a cross-over connection 213. A valve214 is removably supported in the flow conductor 211 for controllingcommunication with the cross-over connection. The valve includes a stem215 supporting a pair of spaced upper and lower valve members 220 and221, respectively, movable along a bore portion 222. An annular valveseat 223 is disposed at the lower end of the bore 222 to cooperate withthe lower valve member 221 for shutting oficommunication to the lowerflow conductor portion 211a. A by-pass line 224 is connected into theflow conductor 211 around the valve 214. The by-pass line communicateswith the flow conductor 211 through an upper port 225 above the valve214 and through a lower port 230 with the valve bore 222 above the valveseat 223 below the upper end position of the lower valve member 221. Thevalve stem 215 is biased upwardly by a spring 216. A port 231 in theflow conductor 211 communicates with the valve bore 222 above the uppervalve member 220. At the upper position of the valve 214 shown in FIG.12,

the flow conductors 210 and 211 are open to the surface and are isolatedfrom each other and from the casing annulus 54. The upper valve member220 is disposed in the bore 222 between the port 231 and the cross-overconnection 213, precluding casing annulus communication with theconductor 210. The lower valve member 221 is disposed in the bore 222between the port 230 and the cross-over connection, preventingcommunication between the flow conductors 210 and 21 1. Any pressurechanges in the flow conductor 210 communicated through the cross-overconnection are applied equally to the upper valve member 220 and thelower valve member 221 so that pressure variations in the flow conductor210 do not affect the position of the valve when the valve is at theupper end position. Fluids may flow from the lower flow conductorportion 211a upwardly through the lower port 230, the by-pass line 224,and the upper port 225 into the upper flow conductor portion 211 throughwhich the fluids flow to the well head. A sufficient increase in thecasing annulus pressure applied through the port 231 to the upper valvemember 220 forces the valve downwardly against the combined force of thespring 216 and the pressure in the flow conductor 211 as appliedupwardly to the lower valve member 221. The valve stem 215 along withthe upper and lower valve members 220 and 221 moves downwardly until thelower valve member seats on the annular surface 223 below the port 230.At such lower valve position the upper valve member is disposed belowthe cross-over connection 213 so that the well annulus 54 communicateswith the flow conductor 210 through the port 231, the bore 222 above theupper valve member and the cross-over connection. The movement of theupper valve member below the cross-over connection preventscommunication between the flow conductors 210 and 211 while the movementof the lower valve member against the seat 223 isolates the lower flowconductor portion 211a. At this lower valve position the upward forceson the valve are the force of the spring 216 and the force of thepressure in the lower conductor portion 211a below the lower valvemember 221. The downward force on the valve is provided by the annuluspressure in the bore 222 above the upper valve member 220. So long asthis downward force exceeds the upward force on the valve, the well maybe circulated in either direction between the flow conductor 210 and thecasing annulus 54. During such circulation the upper and lower sectionsof the flow conductor 211 are isolated from each other and from theconductor 210 and the annulus 54. When return of the valve upwardly isdesired, the pressure is lowered in the casing annulus and the flowconductor 210 to a level sufiicient to permit the spring 216 and thepressure in the lower flow conductor portion 211a to return the valveupwardly so that the well may again be produced through both of the flowconductors 210 and 211.

FIGS. 14 and show a valve arrangement which functions in the same way asthe valve system of FIGS. 12 and 13, utilizing, however, a differentvalve design. The well flow conductor system, including the by-pass line224, shown in FIGS. 14 and 15, is identical to that shown and describedwith reference to FIGS. 12 and 13 and, thus, identical referencenumerals to those in FIGS. 12 and 13 are used in FIGS. 14 and 15 foridentical components of the well system. A removable valve 240 issupported in the flow conductor 211 for controlling the flow functionsof the flow conductor 211 and the communication between the casingannulus and the flow conductor 210. The valve includes a stem 241 biasedupwardly by a spring 242. A valve member 243 is supported on the stemfor movement between the upper end position shown in FIG. 14 and thelower end position of FIG. 15. The valve member has a solid lowerportion 244 supporting a pair of longitudinally spaced external annularring seals 245 and 250 which seal around the lower valve member portionwith the surface of the bore 222. The valve member has an upper portion251 provided with a chamber 252 and a lower port 253 and upper ports 254opening into the chamber. A ring seal 255 is disposed around the uppervalve member portion between the port 253 and the ports 254. At theupper position of the valve member shown in FIG. 14, one zone of thewell is produced through the flow conductor 210 while another zone isproduced through the lower flow conductor portion 2110, the by-pass line224 around the valve 240, and the upper portion of the flow conductor211. The ring seals 245 and 250 on the valve member 243 are above andbelow the cross-over connection 213 so that the flow conductor 210 isisolated from either the well annulus and the flow conductor 211. Whilethe casing annulus pressure communicates with the bore 222 through theport 231, into the valve member chamber 252 through the ports 254, andfurther into the valve bore 222 through the port 253 below the ring seal255, the middle ring seal 250 prevents such casing annulus pressure frombeing applied to the cross-over connection 213 at the upper end positionof the valve. The upward forces on the valve are provided by the spring242 and the pressure in the flow conductor 211 on the valve member overthe area defined by the lower ring seal 245. The pressure from the flowconductor 210 through the cross-over connection 213 is applied equallyto the upper ring seal 250 and the lower ring seal 245 providingcounterbalancing upward and downward forces on the valve member. The netdownward force is provided by the pressure in the casing annulus on thevalve member as applied through the port 231 over the area defined bythe ring seal 255 or 250. The ring seals 250 and 255 seal the same area;the pressures applied to the ring seals from within the valve chamber252 through the port 253 are equal both upwardly and downwardly so thatthe net downward force is applied over the area of the ring seal 255resulting from the annulus pressure. An increase in the annulus pressuresufficient to overcome the spring 242 and the upward force on the valvemember from the pressure in the flow conductor 211 forces the valvemember downwardly to the lower end position of FIG. 15. At the lower endposition of the valve member, the casing annulus 54 communicates withthe flow conductor 210 through the valve member ports 254, the valvechamber 252, and the valve member port 253 into the cross-overconnection 213. The lower end of the valve member engages the valve seat223, shutting off communication to the lower conductor portion 211a sothat the upper and lower portions of the flow conductor 211 are isolatedwhile the casing annulus 54 communicates with the flow conductor 211.Reduction in the pressure in the casing annulus and flow conductor 210permits the valve to move back upwardly to the upper end position ofFIG. 14. Thus, this form of valve arrangement is casing pressureresponsive to communicate the casing annulus with one of the flowconductors while isolating the upper and lower portions of the other ofthe flow conductors at one position of the valve, and permittingsimultaneous production through both of the flow conductors which areisolated from each other and from the casing at the other position ofthe valve.

The well valve arrangement shown in FIGS. 16 and 17 utilizes the samewell flow conductor system described and illustrated in FIGS. 12-14 and,thus, like components of such system are identified by like referencenumerals as used in FIGS. 12-14. A valve 250 is removably supported inthe flow conductor 211 for isolating the casing annulus and the flowconductors in the position shown in FIG. 16 and for communicating thecasing annulus with the flow conductor 211 in the valve position of FIG.17. The valve 250 has a valve stem 251 biased in an upward direction byspring 252 and supporting a hollow valve member 253. The valve memberhas upper ports 254 and a lower port 255 which communicate with an innerchamber 260 of the valve member. The valve member supports lower,intermediate, and upper external ring seals 261, 262, and 263 which sealaround the valve member and the surface defining the bore 222. The ringseals 261 and 262 are disposed on opposite sides of the cross-overconnection 213 at both the upper and lower positions of the valvemember, thereby isolating the flow conductor 210 through the crossoverconnection from both the casing annulus and the flow conductor 211 atall times. At the upper position of the valve member shown in FIG. 16fluids may flow to the surface in both of the flow conductors 210 and211, with the fluids in 211 by-passing the valve 250 in the by-pass line224. While fluids from the annulus 54 communicate with the valve memberthrough the port 231, the several ring seals around the valve memberprevent annulus pressure from being exposed to either of the flowconductors. For example, annulus pressure exists within the valvechamber 260 in the valve member, and thus exists around the valve memberbecause of the port 255 between the ring seals 261 and 262, with thering seal 261 preventing communication into the flow conductor 211. Asufficient increase in the casing annulus pressure through the port 231to the valve member forces the valve member downwardly to the lower endposition seated against the valve seat 223. At this valve position theconductor 210 remains isolated from the other portions of the wellsystem, the lower conductor portion 211a is shut off by the seating ofthe lower end of the valve member against the surface 223, while thecasing annulus is communicated with the flow conductor 211 above theseat 223. The well may be circulated between the well conductor 211 andthe casing annulus along a path defined by the by-pass line 224, theport 230, and the valve member port 255, and the valve chamber 260, theports 254 in the valve member, and the flow conductor 231 to the casingannulus 54. So long as the pressure in the intercommunicating casingannulus and flow conductor 211 provides a force on the valve memberexceeding the upward force of the spring 252 and the pressure below thevalve member in the lower flow conductor portion 2110, the valve remainsat the lower end position. A change in the pressure relationshipssufficient to permit the pressure below the valve member with the forceof the spring to lift the valve upwardly returns the valve to theposition of FIG. 16 isolating the casing annulus and the two flowconductors to again permit dual production from the well through theflow conductors.

The well valve arrangement shown in FIG. 18 uses the same flow conductorsystem shown in the arrangement of FIGS. 1217 and, thus, like referencenumerals are used in FIGS. 18 and 19 to denote like flow conductorcomponents A valve 270 is releasably supported in the flow conductor 211for isolating the two flow conductors 210 and 211 from each other duringdual production of the well and for communicating the conductors witheach other during well servicing procedures. The valve 270 has a stem271 biased upwardly by a spring 272 and provided with a hollow valvemember 273 movable in the bore 222. The valve member has fourlongitudinally spaced external ring seals 274, 275, 280, and 281 forsealing around the member with the wall of the bore 222. An upper port282 in the valve member communicates with a chamber 283 provided in themember while a lower port 284 in the member communicates with the valvechamber. The upper port is disposed between the ring seals 274 and 275;the lower port is disposed between the lower pair of ring seals 280 and281. At the upper position of the valve shown in FIG. 18 the casingannulus 54 and the flow conductors 210 and 211 are all isolated fromeach other. The ring seals 275 and 280 prevent communication along thevalve member within the bore 222 from the cross-over connection 213; theupper ring seal 274 prevents fluid communication along the valve memberfrom the port 231; and the lower end ring seal 281 prevents fluidcommunication upwardly along the valve member from the flow conductor211. Since the pressure from the flow conductor 210 as transmittedthrough the cross-over connection 213 applies equal upward and downwardforces on the valve member by virtue of the identical sealed areasdefined by the ring seals 275 and 280, pressure variations in the flowconductor 210 at the upper position of the valve in FIG. 18 do notaffect the valve position. Upward forces on the valve are provided bythe spring 272 and the pressure in the flow conductor 211 acting overthe area sealed by the ring seal 281, and a downward force is applied bythe pressure in the annulus 54 through the port 231 to the area sealedby the ring seal 274. An increase in the casing annulus pressure to asuflicient value forces the valve member downwardly to the position ofFIG. 19 against the force of the spring and the upward force of thepressure in the flow conductor 211. The valve member is forced againstthe valve seat 223 sealing off the lower flow conductor portion 211a.The upper valve member port 282 is aligned with the cross-overconnection 213, and the lower valve member port is aligned with the flowconductor port 230 leading to the by-pass line 224 so that the flowconductors 210 and 211 communicate through the chamber 283 of the valvemember. The casing annulus remains isolated from both of the flowconductors. So long as the downward force of the casing pressure throughthe port 231 on the valve member exceeds the upward force of thepressure in the lower flow conductor portion 211a and the spring 272,the valve member stays at a lower end position to permit fluid flowbetween the flow conductors in either direction through the valve memberand the cross-over connection for well servicing purposes. A reductionin the casing pressure applied to the valve member permits the springand the pressure in the lower flow conductor portion 211a to lift thevalve back to an upper end position to again isolate the flow conductorsfrom each other. Thus, the valve member effectively communicates andisolates the flow conductors while maintaining the casing annulusisolated and is operable responsive to variations in the casing annuluspressure relative to the pressure in the flow conductor 211.

FIGS. 20 and 21 show a still further form of valve system using theconduit arrangement shown in FIGS. 12-17, the components of which arereferred to by the same reference numerals used in such figures, Aremovable valve 290 is supported in the flow conductor 211 forcontrolling the flow relationship between the casing annulus 54 and theflow conductors 210 and 211. The valve has a valve stem 291 biased in anupward direction by a spring 292 and supporting a hollow valve member293 which is movable between an upper end position as shown in FIG. 20and a lower end position illustrated in FIG. 21. At the upper endposition of FIG. 20, the flow conductors 210 and 211 are isolated fromeach other and from the casing annulus 54 so that the well may besimultaneously produced through both flow conductors. At the lower endposition of FIG, 21 the well annulus and both of the flow conductors areall in communication with each other while the lower portion 211a of theflow conductor 211 is isolated from the remainder of the system. Thevalve member 293 has an upper pair of spaced external ring seals 294 and295 and a lower pair of spaced external ring seals 300 and 301. Thevalve member has a central valve chamber 302 which defines a passagethrough the member for flow between the flow conductors and the casingannulus. The valve member has upper end ports 303, an upper side port304, and a lower side port 305, all of which communicate with thechamber 302 in the valve member. The upper side port 304 is locatedbetween the ring seals 294 and 295 and is alignable with the cross-overconnection 231 when the valve member is at the lower end position ofFIG. 21. Similarly, the lower side port 305 is located between the ringseals 300 and 301 and is alignable with the flow conductor port 230leading to the by-pass line 224 when the valve is at the lower endposition. With the valve at the upper end position of FIG. 20, theupward forces on the valve member are provided by the spring 292 and thepressure in the flow conductor 211 below the valve member applied overthe area defined by the ring seal 301. A downward force on the valvemember is provided by the casing annulus pressure applied into the bore222 to the valve member over an area defined by the ring seal 294. Itwill be recognized that the pressure in the casing annulus iscommunicated through the ports 303 into the chamber 302 of the valvemember and outwardly through the ports 304 and 305 into the bore 222.This pressure, however, does not affect the valve member due to thepresence of the ring seals 294 and 295 spanning the port 304 and thering seals 300 and 301 spanning the port 305 so that the casing annuluspressure as communicated through the valve member at the upper endposition of the valve member

1. A well system for producing and servicing a well comprising: meansdefining a plurality of flow passages in a well; means defining across-over connection between at least two of said flow passages; andvalve means disposed in a first of said flow passages for controllingcommunication between at least two of said flow passages through saidcross-over connection, said valve means isolating said two flow passagesfrom each other at a first position of said valve means andcommunicating said two flow passages with each other at a secondposition of said valve means, said valve means being movable betweensaid positions responsive only to a pressure valve exterior of saidfirst flow passage in excess of the pressure in said first flow passage.2. A well system in accordance with claim 1 wherein said valve means atsaid second position isolates the portion of said first flow passagebelow said valve means from the remainder of said flow passages whilecommunicating at least said two flow passages.
 3. A well system inaccordance with claim 2 wherein the fluid pressure in said first flowpassage during normal well production at said first position of saidvalve means is higher than the pressure exterior of said first passage,a relative increase in which moves said valve means to said secondpoSition.
 4. A well system in accordance with claim 2 wherein said firstflow passage is defined by a flow conductor adapted to be supported in awell, and said valve means is disposed in said flow conductor at meansincluding said cross-over connection to communicate said connection withsaid flow conductor when said valve means is at said second position andto isolate said flow conductor below said valve means from saidconnection when said valve means is at said first position.
 5. A wellsystem in accordance with claim 4 including a landing nipple comprisinga hollow body member spaced within said flow conductor defining a borein which said valve means is disposed, said cross-over connectionopening into said bore, means defining a valve seat in said body memberfor engagement by said valve means at said second position, and meansdefining a port communicating said bore of said body member with a spacein said flow conductor around said body member whereby fluid flowsthrough said space from below said valve means into said flow conductorabove said valve means when said valve means is at said first position.6. A well system in accordance with claim 2 wherein first and secondflow passages are defined by two flow conductors interconnected by saidcross-over connection, said flow conductors being isolated from thecasing annulus of said well, said valve means being engaged in a firstof said conductors defining said first flow passage, said firstconductor having a by-pass for flow around said valve means when saidvalve means is at said first position between said by-pass and saidcross-over connection and said by-pass permitting communication throughsaid cross-over connection to said second flow conductor from said firstflow conductor above said valve means when said valve means is at saidsecond position, said valve means being movable from said first to saidsecond position by a pressure in said second flow conductor higher thanthe pressure in said first flow conductor.
 7. A well system inaccordance with claim 2 wherein first and second flow passages aredefined by first and second flow conductors and a third flow passage isdefined by the casing annulus in said well around said flow conductors,said cross-over connection interconnecting said first and second flowconductors port means provided in said first conductor spaced above saidcross-over connection communicating with said third flow passage, aby-pass line connected at opposite ends at spaced locations into saidfirst flow conductor, the lower end of said by-pass line connecting intosaid first flow conductor at a location spaced below said cross-overconnection, said valve means being disposed in said first flow conductorat a location permitting fluid flow around said valve means from belowsaid valve means to above said valve means through said by-pass linewhen said valve means is at a first position, said valve means includingan upper valve member disposed and movable between said cross-overconnection and said port to said third flow passage whereby said thirdflow passage is isolated at all times from said cross-over connectionand said valve member is responsive to pressure in said third flowpassage, and said valve means includes a second valve member movablewith said first valve member and disposed at said first position of saidvalve means between said cross-over connection and said lower end ofsaid by-pass line into said first flow conductor whereby said flowconductors are isolated from each other at said first position of saidvalve means, said second valve member moving at the said second positionof said valve means to a position below said connection of said lowerend of said by-pass line into said first flow conductor forcommunicating said first and second flow conductors with each otherwhile isolating the lower portion of said first flow conductor belowsaid valve means.
 8. A well system in accordance with claim 2 whereinfirst and second flow passages are defined by flow conductors in saidwell and a third flow passage is defined by a well annulus around saidflow conductors, said cross-over connection interconnecting said firstand second conductors, said first conductor having a port spaced abovesaid cross-over connection communicating said conductor with said thirdflow passage, said valve means being disposed in said first flowconductor, said first flow conductor having a by-pass line connected atan upper end into said flow conductor above said valve means and at alower end into said flow conductor below said cross-over connection,said valve means having spaced first and second valve members, at saidfirst position of said valve means said first valve member beingdisposed between said port to said third flow passage and saidcross-over connection and said second valve member being disposedbetween said cross-over connection and the connection of said lower endof said by-pass line into said first flow conductor whereby said firstand second flow conductors are isolated each from the other and saidthird flow passage is isolated from both of said flow conductors, saidvalve means being movable to said second position at which said firstvalve member is disposed between said cross-over connection and saidconnection of said lower end of said by-pass line into said first flowconductor and said second valve member is disposed in said first flowconductor below said connection of said lower end of said by-pass lineto said flow conductor whereby said third flow passage and said secondflow conductor communicate with each other through said cross-overconnection and said side port in said first flow conductor, said lowerportion of said first flow conductor is isolated from the upper portionof said conductor, and said upper portion of said first flow conductoris isolated from said second flow conductor, said valve being movable tosaid second position responsive to a pressure in said third flow passagein excess of the pressure in said first flow conductor.
 9. A well systemin accordance with claim 2 wherein first and second flow passages aredefined by first and second flow conductors and said cross-overconnection interconnects said conductors, said first conductor having aport spaced above said cross-over connection communicating with a thirdflow passage defined in said well around said flow conductors, saidvalve means being disposed in said first flow conductor, a by-pass linealong said first flow conductor around said valve means connected at anupper end to said first flow conductor above said valve means and at alower end below said cross-over connection, said valve means including amovable valve member for isolating said first and second flow conductorsfrom each other and from said third flow passage at a first valveposition while allowing upward flow along said first flow conductor andsaid by-pass line, and said valve member at a second positioncommunicating said second flow conductor with said third flow passagethrough said cross-over connection while isolating upper and lowerportions of said first flow conductor from each other and from saidsecond flow conductor and said third flow passage, said valve memberbeing movable to said second position responsive to a pressure in saidthird flow passage in excess of the pressure in said first flowconductor.
 10. A well system in accordance with claim 2 wherein firstand second flow passages are defined by first and second flow conductorsand said cross-over connection interconnects said flow conductors, athird flow passage is defined by the annular space in said well aroundsaid flow conductors, said first flow conductor having a side portspaced above said cross-over connection communicating with said thirdflow passage, said valve means being disposed in said first flowconductor, a by-pass line connected along said first flow conductoraround said valve means, the upper end of said by-pass line beingconnected into said first flow conductor abOve said valve means and thelower end of said by-pass line being connected into said first flowconductor at a location spaced below said cross-over connection, saidvalve means including a valve member having means at a first positionfor isolating said first and second flow conductors from each other andfrom said third flow passage while permitting flow along said firstconductor and by-pass line, said valve member having means at a secondposition communicating said third flow passage with the portion of saidfirst flow conductor above said valve means while isolating the portionof said first flow conductor below said valve means and isolating saidsecond flow conductor from said first conductor and said third flowpassage, said valve member being movable to said second positionresponsive to a pressure in said third flow passage in excess of thepressure in said first conductor.
 11. A well system in accordance withclaim 2 wherein said first and second flow passages are defined by firstand second flow conductors interconnected by said cross-over connectionand a third flow passage is defined by the annular space around saidflow conductors, said first flow conductor having a side port above saidcross-over connection communicating with said third flow passage, saidvalve means being disposed in said first flow conductor at saidcross-over connection, a by-pass line connected into said first flowconductor, the upper end of said by-pass line being connected into saidconductor above said valve means, and the lower end of said by-pass linebeing connected into said conductor at a location spaced below saidcross-over connection, said valve means including a valve member movablein said flow conductor and having means for isolating said first andsecond flow conductors and said third flow passage from each other at afirst position while permitting flow along said first conductor andby-pass line, and at a second valve member position for communicatingsaid first conductor above said valve means with said second flowconductor through said cross-over connection while isolating said thirdflow passage and said first conductor below said valve means, said valvemember being movable to said second position responsive to a pressure insaid third flow passage in excess of the pressure in said first flowpassage.
 12. A well system in accordance with claim 2 wherein first andsecond flow passages are defined by first and second flow conductorsinterconnected by said cross-over connection and a third flow passage isdefined by an annular space in said well around said flow conductors,said first flow conductor having a port spaced above said cross-overconnection communicating with said third flow passage, said valve meansbeing disposed in said first flow conductor, a by-pass line connectedinto said first flow conductor from above said valve means to a locationspaced below said cross-over connection, said valve means including avalve member having means for isolating said first and second flowconductors and said third flow passage from each other while permittingflow along said first conductor and by-pass line at a first valve memberposition and at a second valve member position isolating a lower portionof said first conductor below said valve means while communicating saidflow conductor above said valve means with said third flow passage andwith said second flow conductor through said cross-over connection, saidvalve member being movable to said second position responsive to apressure in said first flow passage below the pressure in said thirdflow passage.
 13. A well system in accordance with claim 2 wherein saidfirst and second flow passages are defined by first and second flowconductors and said cross-over connection connects said conductors,means for supporting a valve in said first conductor at said cross-overconnection, said valve being movable between a first position at whichsaid first and second flow conductors are isolated from each other anD asecond position at which said first conductor above said valve iscommunicated with said second flow conductor and the portion of saidfirst conductor below said valve is isolated, and a valve in said secondflow conductor at said cross-over connection movable between a firstposition at which said flow conductors communicate through saidcross-over connection and a second position at which said flowconductors are isolated from each other at said cross-over connection.14. A well system in accordance with claim 13 wherein said valve in saidsecond flow conductor is a sliding sleeve valve.
 15. A well system inaccordance with claim 2 including means defining first and second flowpassages comprising first and second flow conductors interconnected bysaid cross-over connection, said valve means being releasably lockablein either of said flow conductors at said cross-over connection, aby-pass line connected into each of said flow conductors from above saidvalve means to a location spaced below said cross-over connection, saidvalve means having a valve member disposed at a first position betweensaid cross-over connection and the connection of the lower end of theby-pass line into the flow conductor in which said valve means is lockedwhereby at said first position of said valve member said first andsecond flow conductors are isolated from each other, and said valvemember being movable to a second position responsive to a pressure inthe other flow conductor in excess of the pressure in the flow conductorin which said valve means is locked, said valve member isolating thelower portion of the flow conductor in which said valve means is lockedand communicating the upper portion of such flow conductor with theother flow conductor through said cross-over connection.
 16. A wellsystem for producing and servicing a well comprising: means defining aplurality of flow passages in said well for well fluids and servicefluids flow; means for cross flow between at least two of said flowpassages; and means for supporting a valve in a first of said flowpassages for selectively isolating and communicating said two passagesconnected with said cross-flow means responsive only to a pressureexterior of said first flow passage in excess of the pressure in saidfirst flow passage.
 17. A well system in accordance with claim 16including a flow control valve in said valve supporting means, saidvalve being movable between a first valve position at which said twoflow passages communicatable through said cross flow passage areisolated from each other and a second valve member position at whichsaid two flow passages communicate with each other, said valve beingmovable between said positions responsive to a pressure differentialacross said valve means between said first flow passage and one of saidflow passages other than said first flow passage.
 18. A well system inaccordance with claim 16 wherein said two flow passages connected withsaid means for cross flow are defined by first and second flowconductors, said first flow conductor having a side-pocket landingnipple having a side pocket for said valve and communicating with saidmeans for cross flow.
 19. A well system in accordance with claim 18wherein said second flow conductor includes a side-pocket type landingnipple, and the side pockets of both of said landing nipples communicatethrough said means for cross flow.
 20. A well system in accordance withclaim 19 wherein said landing nipples are longitudinally aligned witheach other.
 21. A well system in accordance with claim 19 wherein saidlanding nipples are displaced longitudinally from each other and nestedtogether in an over-under relationship, and said means for cross flow isdefined by conduit means extending longitudinally between side ports insaid side pockets of said landing nipples.
 22. A well system inaccordance with claim 16 wherein said two flow passages are defined inan integral unit for connection with first and secOnd flow conductors,one side of said unit having a longitudinally extending side-pocket typelanding nipple and the other side of said unit having a longitudinalflow passage, and said unit having said means for cross flow connectingthe side pocket of said landing nipple and said longitudinal flowpassage.
 23. A well system in accordance with claim 16 wherein said twoflow passages are defined in an integral unit having side-by-sideside-pocket type landing nipples formed therein, the side pockets ofsaid nipples communicating through said means for cross flow wherebysaid valve is positionable in either of said side pockets forcontrolling flow between said landing nipples.